Clockwork for mechanical fuses for artillery projectiles



March 16 1926. 1,577,391

A. VARAUDv GLOCKWORK FOR MECHANICAL FUSES FOR ARTILLERY PROJECTILES Filed May l, 1925 171W am-2, 28.

-If-lseofffff Patented Mar. 16, 1926,

` ,ensei erica.

lANDR VARA'UD, 0F GENEVA, SWITZERLAND.

i CLOGKWORK FOR MECHANCAL FUSES FOR ARTLLERY PROJEGTILES.

Application filed May 1,

To all whom, t may concern:

Be it known that I, ANDR VARAUD, a citizen of France, residing at Geneva, Canton of Geneva, in the Confederation of Switzerland, have invented certain new and useful l Improvements in Clockworks for Mechanical Fuses for Artillery Projectiles, of which the following is a specification.

The present invention relates to clockwork for mechanical fuses for artillery pro jeetiles and more particularly to the devices comprising the regulator and escapement mechanism used for controlling the operation of the clockwork.

Heretofore in a clockwork for similar purposes it has been proposed to employ a balance regulator carried by a spring and also to use an escapement such as is com monly employed in watches, but heretofore it has been practically impossible to construct a device of this kind capable not only of resisting the effect of inertia produced at the moment of firing the projectile, but also of resisting the disturbing act-ion of centrifugal force during the trajectory of the projectile, and which finally is capable of giving to the balance free oscillations of great amplitude in order to regulate the transmision of the motive power.

In operating the balance of all these known devices, it is practically impossible io use a spiral spring arranged in the geometrical axis of the fuse owing to the fact that on one part the centrifugal force, acting on the convolutions of the spiral, disturbs'the device and destroys the isochronism of the oscillations of the balance, and on the other part the deformations or jerks produced by the effects of inertia at the moment of the departure of the projectile tend to negative the function of the device altogether. l

Attempts have been made to replace the springs, as they have grown classic in horolog 1, either by a flexible blade traversing the axle of the balance and fixed at both of its ends with the required play for working under flexion, that is to sayv it was sought to substitute for the former spiral springs a torsion spring arranged in the axis of rotation of the projectile. It has 'thereby been possible for the balance spring te support the check due to inertia and to elevate te a certain extent the ine'@neen 1925. Serial No. 27,121.

iences resulting from the pertiubing action of the centrifugal force.

But it is evident that these springs have necessarily but little power and elasticity and it has not been possible to give to the oscillations of the balance an adequate isochronism and a sufficiently great amplitude to assure a perfect regularity of the transmission of the motive power and to use an escapement giving free oscillations to the balance. The detent escapements, the free lever escapements and the horizontal (cylinder) escapements being too delicate or unemployable in this particular case, it has been necessary to adhere to the anchor recoil or mixed eseapement that is to say to an escapement having a slight rest or locking in which the amplitude of the oscillations of the balance is limited by the base or bottom of the teeth of the escapement wheel. On the other hand the little elasticity of these springs .does not permit to have them suiiciently strong to be adapted for maintainingl the isoehronism of the oscillations of the balance in spite ofthe irregularities which may occur in the action of the centrifugal force, when,'for example, the projectile `does not turn exactly round its geometrical axis,-a phenomenon known as nutation. A

Heretofore it has been proposed to employ a cylindrical escapement with pins and in which the axes of the balance and that of the escapement wheel are parallel whereby the balance is given free oscillations of relatively large amplitude, but it has been found that the pins as heretofore employed were too delicate to answer the required purposes,

Vthe rests or stops of the escapement wheel,

being determined .by the tangential contact of a pin with the periphery of a relatively large cylinder also, created frietional forces too great to permit the balance to describe under normal conditions its supplementary arcs. Now, in a clockwork for mechanical fuses, more than in any other, owing` to the Yvariations in motive power caused by the more .or less great intensity of the centrifugal force, it is necessary to be able to give to the balance oscillations of great amplitude if one wishgs to obtain strict isochronism of these oscillations which is, indispensable for the exact rate of the clockwork`- The clockwork which is the object of this inventien does come up1 to all these require= for mechanical fuses by theifact that it coinprises acylindrical balance spiral couched ransversely inthe fuse and preferably perpendicular to the axis of rotation of the projectile, a supporting` member upon which .this spiral rests momentarily at the time of the departure of theprojectile upon beingy fired7 and a dead-beat escapement which makes it possible to give the balance oscillations of relatively large amplitude.

The annexed design represents by ywayof example a constructional form'of the device being` the object of the invention.

Fig. 1 is a partial section 'made along the line l-l of Fig. 2 of this form, indicating in dotted lines apart of thetrain ofthe movement and of thebalance.

wFigr2v is a transversal section drawn along the angle-line 2-2 of Fig'. 1.

riccording yto the drawing the last wheel ofthe clockwork gear train of -the fuse (of which only the` part where the regulator and the escapement are lplaced is represented) is a bevelled pinion 1 fixedv uponone of the ends of a little spindle 2 revolving in a U-shaped bearing' 3., 'In the middle of this spindle vis 'fastened by means of Va radial screw 4L a double, esca-pement-Vwheel 5 of the alternate tooth type well known in itself, but which has heretofore lbeen used lonly for clocks and calledvafter its inventorthe Garnier escapement wheel. This wheel cooperates withl a 'collet in the form of a sector 6 fixed upon the spindle or rod 7 of the balance 8. The opening of this sector is between 160. and 2000. The impulsesare yby the pressure of the inclined parts `of the teeth of the double wheel upon the section of the sector alternatively transmitted first in one direction and then in the other. on

either side of the spindle 7 whilst the lockings take place when thepoint of oneof the teeth of the wheel 5 rests upon the upper face of the sector 6. In order toy facilitate the disengagement this face is slightly inclined atv 9 towards the .end face of the sector. Y

The spindle revolves in a already known in the axis -y/kk of the fuse between two plates 10 and 11 of said fuse and carries upon 'its upper part the ybalance Swhich presents two blades 12inalignment with one another. Eachof these blades .is a

lthin and iiexible strip of metal which carries on its free end a .small weight13. An in-Y termediateplatev 14 limits the bending of these blades 12 which is produced by inertia v of the projectile to which the fuseisfixed. Y y

rlhe spindle 7 carries likewise a bevell-ed pinion 1 5 which engageswith a second bevelledgear 17 attached to one endof a small radial spindle 18 rotating ina'bearing 19. At its other end, this radial spindle 18 manner carries a stud 2O for fixing one of thel ends of the cylindrical or helical spring 21.01' the balance; lwhich spring is radially couched across the fuse and whose axis is consequently perpendicular to the axis -y/ ofthe latter 'Theother end of this balance spring 21 is attachedto a split ringw22 which is adjustable in angular position on'a cylinrof the split-ring 25 with regard to the'ring 22, the usefullength of said spring will be regulated. The ring 22V as well as the splitring 26 are milled at their periphery to facilitate being gripped by hand.v A regulating screw 28 is adjustable in the stud`24- and makes it possibleto regulate the axial position of the spindle 18 with regard to the bearing 19 so as to assure the correct mesh.-

ing of the bevellcd pinions 15 and 17 regardless 'of the action of the centrifugal force developed by the rotation of the projectile to which the fuse has been fitted. Y

A part of the bearing 19 extends beneath the balance spring 21 so as to act asia supporting member at the moment of the departure ofthe projectile. i y l The working of this form of embodiment of the inventionisas follows: i

Thefuse is mountedin the pointed part ofthe projectile so that its axis -g/ coincides with theaxis of the latter'and the balance 8 l2 Vis'locked by 'any'lappropriate means (not represented) 'in its arrestedpositfion until `the Afiring moment. Said lock-k ing means are at the moment of the depart'urel of the projectile by the inertia or byy centrifugal force automatically withdrawn. A

The-relative position ofthe balance and of the escapement wheel is regulated in the Y course of the manufacture of the clockwork by means of the split-ring 22 so that one of the cogs of the escapement wheel is normally ready in position to give a'rst im-v1 pulse to the balance, whilst the spring 21 is lafterwards regulated Vby means ofthe split ring or racket 26. As soon asv the liberation of the balance takes place, the

escapem'ent wheel thus gives an impulse to balance in the opposite direction and the following cog Comes into the position of rest and so forth.

It would be possible to apply two cylindrical springs for the balance and the latter might have more than two blades or miO'ht comprise a full flywheel.

One could reverse the arrangement of the balance and that of the escapement wheel; this latter being then placed parallel to the axis of the fuse whilst the spindle 7 and the spindle 18 of the spring 21 become one and the same. In this case the bevelled gears 15, 17 Would of course be eliminated.

IVhat I claim is:

1. In a clockwork for mechanical fuses for artillery projectiles, a balance, a cylindrical spiral so placed that the axis thereof is transverse of the fuse and perpendicular to the axis of rotation of the projectile, a supporting member upon which said spiral momentarily rests at the time of the departure of the projectile upon being fired, and a dead-beat escapement whereby oscillations of relatively large amplitude are given to the balance.

2. In a regulator for clock-Work operated fuses for artillery projectiles, a balance, an arbor for the same, an escapement Wheel, an arbor for the same, the arbors for the said balance and escapement Wheel being perpendicular to each other, and a spiral spring for regulating the action of the said balance and escapement Wheel, the axis of the spiral spring` being transversely of the fuse and perpendicular to the axis of the projectile to which the fuse is attached.

3. In a regulator for clock-Work operated fuses for artillery projectiles, a balance, an arbor for the same, a sector-like shoulder on the arbor of the balance, an escapement Wheel adapted to engage the said sector-like shoulder, and a spiral spring for regulating the action of the balance and escap-ement Wheel, the axis of the spiral Spring' being transversely of the fuse and perpendicular to the axis of the projectile to which the fuse is attached.

4. In a clock-Work for mechanical fuses for artillery projectiles, a balance, an arbor for the same, an escapement Wheel for actuating the balance, a spiral spring, an arbor for the same, and meshing bevel gears on the said arbors, the axis of the said spiral spring and the arbor therefor being transversely of the fuse and perpemlicular to the axis of the projectile to which the fuse is attached.

5. In a clock-work f'or mechanical fuses for artillery projectiles, a balance, an arbor therefor, an escapcment Wheel, a shoulder on the arbor of the balance adapted to be engaged by the escapement Wheel for actuating the balance, a spiral spring, an arbor for the same, meshing bevel gears on the said arbors, and means for adjustii'ig the tension of the said spiral spring, the axis of the said spiral spring and its arbor being transversely of the fuse and perpendicular to the axis of the projectile to which the fuse is attached.

6. In a clock-Work for mechanical fuses for artillery projectiles, a balance, an arbor therefor, an escape/ment Wheel, a shoulder on the arbor of the balance adapted to be engaged by the escapement wheel for actuatingl the balance, a spiral spring, an arbor for the same, meshing bevel gears on the said arbors, a stud at one end of the arbor of the spiral spring, a split ring to which the opposite end of the spiral spring is connected, and means for revolubly adjusting and securing the split ring in position to determine the tension of the spiral spring, the axis of the said spiral spring and its arbor being transversely of the fuse and perpendicular to the axis of the projectile to which the fuse is attached.

7. In a clock-Work for mechanical fuses for artillery projectiles, a balance, an arbor therefor, a double escapement Wheel, a shoulder on the arbor of the balance, the said shoulder having an inclined edge to facilitate its disengagement u ith the said double escapement Wheel, a spiral spring, an arbor for the same, meshing bevel gears on the said arbo-rs, a stud at one end of the arbor of the spiral spring, a. split ring to which the opposite end of the spiral spring is connected, and means for revolubly adjusting and securing the split ring in position to determine the tension of the spiral spring, the axis of the said spiral spring and its arbor being transversely of the fuse and perpendicular to the axis of thel projectile to which the fuse is attached.

In testimony whereof I have aflixed my signature.

ANDR VARAUD. 

